4b35dcb5e0
I ran into a 4.9 build warning in randconfig testing, starting with the
KAISER patches:
arch/x86/kernel/ldt.c: In function 'alloc_ldt_struct':
arch/x86/include/asm/pgtable_types.h:208:24: error: large integer implicitly truncated to unsigned type [-Werror=overflow]
#define __PAGE_KERNEL (__PAGE_KERNEL_EXEC | _PAGE_NX)
^
arch/x86/kernel/ldt.c:81:6: note: in expansion of macro '__PAGE_KERNEL'
__PAGE_KERNEL);
^~~~~~~~~~~~~
I originally ran into this last year when the patches were part of linux-next,
and tried to work around it by using the proper 'pteval_t' types consistently,
but that caused additional problems.
This takes a much simpler approach, and makes the argument type of the dummy
helper always 64-bit, which is wide enough for any page table layout and
won't hurt since this call is just an empty stub anyway.
Fixes: 8f0baadf2bea ("kaiser: merged update")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
53 lines
1.2 KiB
C
53 lines
1.2 KiB
C
#ifndef _LINUX_KAISER_H
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#define _LINUX_KAISER_H
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#ifdef CONFIG_PAGE_TABLE_ISOLATION
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#include <asm/kaiser.h>
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static inline int kaiser_map_thread_stack(void *stack)
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{
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/*
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* Map that page of kernel stack on which we enter from user context.
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*/
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return kaiser_add_mapping((unsigned long)stack +
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THREAD_SIZE - PAGE_SIZE, PAGE_SIZE, __PAGE_KERNEL);
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}
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static inline void kaiser_unmap_thread_stack(void *stack)
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{
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/*
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* Note: may be called even when kaiser_map_thread_stack() failed.
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*/
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kaiser_remove_mapping((unsigned long)stack +
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THREAD_SIZE - PAGE_SIZE, PAGE_SIZE);
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}
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#else
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/*
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* These stubs are used whenever CONFIG_PAGE_TABLE_ISOLATION is off, which
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* includes architectures that support KAISER, but have it disabled.
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*/
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static inline void kaiser_init(void)
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{
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}
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static inline int kaiser_add_mapping(unsigned long addr,
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unsigned long size, u64 flags)
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{
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return 0;
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}
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static inline void kaiser_remove_mapping(unsigned long start,
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unsigned long size)
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{
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}
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static inline int kaiser_map_thread_stack(void *stack)
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{
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return 0;
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}
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static inline void kaiser_unmap_thread_stack(void *stack)
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{
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}
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#endif /* !CONFIG_PAGE_TABLE_ISOLATION */
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#endif /* _LINUX_KAISER_H */
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